Some power applications include one or more rectifiers to convert AC voltages to DC voltages. For instance, a wireless power receiver may rely on a rectifier to convert an AC voltage input received at a receiving coil into a DC voltage that is relied on by some other part of the wireless power receiver (e.g., a power converter, a load, etc.). A rectifier may be a passive rectifier or a synchronous rectifier (otherwise referred to as “active rectifier”). A passive rectifier may include passive elements (e.g., diodes) and a synchronous rectifier may include active elements (e.g., controllable switches). In either case, the elements of a passive and synchronous rectifier are arranged in a particular configuration (e.g., a half-bridge, an H-bridge configuration) to convert an AC voltage to DC. By using active type elements rather than passive type elements, a synchronous rectifier may have a reduced amount of power loss as compared to a passive rectifier.
In some examples, the active type elements of a synchronous rectifier may be Metal Oxide Semiconductor (MOS) type switches and that each include a parasitic body diode. A body diode of each MOS type switch may act like a passive type element of a passive rectifier. Accordingly, even when each MOS type switch of a synchronous rectifier is operating in a switched-off state, the synchronous rectifier may still perform passive rectification. Accordingly, if a large AC voltage is applied to the input of a synchronous rectifier when the MOS type switches are turned-off, the synchronous rectifier may still output a large DC voltage (e.g., a DC voltage that exceeds the breakthrough voltage of the MOS type switches) that can destroy or at least damage the synchronous rectifier and/or surrounding system.